Composition for tawing leather.



' or compound.

UNITED STATES PATENT OFFICE.

JOSEPH WV. SMITH, OF GIRARD, OHIO, ASSIGNOR OF ONE-THIRD TO CARRIE II.NEl/V, OF YOUNGSTOIVN, OIIIO.

COMPOSITION FOR TAWING LEATHER.

SPECIFICATION forming part of Letters Patent No. 632,208, dated August29, 1899.

Application filed June 16, 1898. Serial No. 683,570. (No specimens.)

T0 at whom it may concern:

Be it known that I, JOSEPH W. SMITH, a citizen of the UnitedStates,residingat Girard, in the county of Trumbull and State of Ohio,have invented certain new and useful Improvements in Compositions ofMatter for Tawing Leather, of which the following is a specification.

My invention relates to the tanning or tawing of leather and issubstantially what is known in the tanners art as a tanning liquor Theclass of compounds for this purpose to which my invention belongs isthat in which chromic oxid is formed in the fabric of the hide to betreated, forming what is commonly known as chrome leather.

I will first disclose the substances entering into my composition orcompound and then define the matter for which I claim protec tion byspecific claim.

The substances entering into the composition and their approximatequantities are as follows, to Wit: chrome alum in the crystallized form,one hundred and fifty pounds; carbonate of soda, seventy-five pounds;hydrated chromic acid, an aqueous solution of chromic trioxid of thestrength of twelve per cent, twelve pounds; hydrochloric acid, used ataspecific gravity of 1.146 and of the strength of 28.61, six gallons;sodium chlorid, ten pounds, and water fifty gallons.

In the preparation of my compound I take, first,Water,twenty-fivegallons; chrome alum, one hundred and fifty pounds; carbonate ofsoda,fifty pounds. Then I take Water,twentyfive gallons; hydrochloricacid, six gallons; hydrated chromic acid, twelve pounds; so

dium carbonate, twenty-five pounds; sodium chlorid, ten pounds. The twopreparations are then intermixed, forming a tawing compound after theterms of my invention.

It is entirely unnecessary to describe the application of the liquor tothe hides and the JOSEPH W. SMITH.

lVitnesses:

E. O. WEAVER, IV. D. STEWART.

